sync code with last improvements from OpenBSD

xserver/mi/miline.h

@@ -0,0 +1,172 @@
+
+/*
+
+Copyright 1994, 1998  The Open Group
+
+Permission to use, copy, modify, distribute, and sell this software and its
+documentation for any purpose is hereby granted without fee, provided that
+the above copyright notice appear in all copies and that both that
+copyright notice and this permission notice appear in supporting
+documentation.
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+Except as contained in this notice, the name of The Open Group shall not be
+used in advertising or otherwise to promote the sale, use or other dealings
+in this Software without prior written authorization from The Open Group.
+
+*/
+
+#ifndef MILINE_H
+
+#include "screenint.h"
+#include "privates.h"
+
+/*
+ * Public definitions used for configuring basic pixelization aspects
+ * of the sample implementation line-drawing routines provided in
+ * {mfb,mi,cfb*} at run-time.
+ */
+
+#define XDECREASING	4
+#define YDECREASING	2
+#define YMAJOR		1
+
+#define OCTANT1		(1 << (YDECREASING))
+#define OCTANT2		(1 << (YDECREASING|YMAJOR))
+#define OCTANT3		(1 << (XDECREASING|YDECREASING|YMAJOR))
+#define OCTANT4		(1 << (XDECREASING|YDECREASING))
+#define OCTANT5		(1 << (XDECREASING))
+#define OCTANT6		(1 << (XDECREASING|YMAJOR))
+#define OCTANT7		(1 << (YMAJOR))
+#define OCTANT8		(1 << (0))
+
+#define XMAJOROCTANTS		(OCTANT1 | OCTANT4 | OCTANT5 | OCTANT8)
+
+#define DEFAULTZEROLINEBIAS	(OCTANT2 | OCTANT3 | OCTANT4 | OCTANT5)
+
+/*
+ * Devices can configure the rendering of routines in mi, mfb, and cfb*
+ * by specifying a thin line bias to be applied to a particular screen
+ * using the following function.  The bias parameter is an OR'ing of
+ * the appropriate OCTANT constants defined above to indicate which
+ * octants to bias a line to prefer an axial step when the Bresenham
+ * error term is exactly zero.  The octants are mapped as follows:
+ *
+ *   \    |    /
+ *    \ 3 | 2 /
+ *     \  |  /
+ *    4 \ | / 1
+ *       \|/
+ *   -----------
+ *       /|\
+ *    5 / | \ 8
+ *     /  |  \
+ *    / 6 | 7 \
+ *   /    |    \
+ *
+ * For more information, see "Ambiguities in Incremental Line Rastering,"
+ * Jack E. Bresenham, IEEE CG&A, May 1987.
+ */
+
+extern _X_EXPORT void miSetZeroLineBias(ScreenPtr /* pScreen */ ,
+                                        unsigned int    /* bias */
+    );
+
+/*
+ * Private definitions needed for drawing thin (zero width) lines
+ * Used by the mi, mfb, and all cfb* components.
+ */
+
+#define X_AXIS	0
+#define Y_AXIS	1
+
+#define OUT_LEFT  0x08
+#define OUT_RIGHT 0x04
+#define OUT_ABOVE 0x02
+#define OUT_BELOW 0x01
+
+#define OUTCODES(_result, _x, _y, _pbox) \
+    if	    ( (_x) <  (_pbox)->x1) (_result) |= OUT_LEFT; \
+    else if ( (_x) >= (_pbox)->x2) (_result) |= OUT_RIGHT; \
+    if	    ( (_y) <  (_pbox)->y1) (_result) |= OUT_ABOVE; \
+    else if ( (_y) >= (_pbox)->y2) (_result) |= OUT_BELOW;
+
+#define MIOUTCODES(outcode, x, y, xmin, ymin, xmax, ymax) \
+{\
+     if (x < xmin) outcode |= OUT_LEFT;\
+     if (x > xmax) outcode |= OUT_RIGHT;\
+     if (y < ymin) outcode |= OUT_ABOVE;\
+     if (y > ymax) outcode |= OUT_BELOW;\
+}
+
+#define SWAPINT(i, j) \
+{  int _t = i;  i = j;  j = _t; }
+
+#define SWAPPT(i, j) \
+{  DDXPointRec _t; _t = i;  i = j; j = _t; }
+
+#define SWAPINT_PAIR(x1, y1, x2, y2)\
+{   int t = x1;  x1 = x2;  x2 = t;\
+        t = y1;  y1 = y2;  y2 = t;\
+}
+
+#define miGetZeroLineBias(_pScreen) ((unsigned long) (unsigned long*)\
+    dixLookupPrivate(&(_pScreen)->devPrivates, miZeroLineScreenKey))
+
+#define CalcLineDeltas(_x1,_y1,_x2,_y2,_adx,_ady,_sx,_sy,_SX,_SY,_octant) \
+    (_octant) = 0;				\
+    (_sx) = (_SX);				\
+    if (((_adx) = (_x2) - (_x1)) < 0) {		\
+	(_adx) = -(_adx);			\
+	(_sx = -(_sx));				\
+	(_octant) |= XDECREASING;		\
+    }						\
+    (_sy) = (_SY);				\
+    if (((_ady) = (_y2) - (_y1)) < 0) {		\
+	(_ady) = -(_ady);			\
+	(_sy = -(_sy));				\
+	(_octant) |= YDECREASING;		\
+    }
+
+#define SetYMajorOctant(_octant)	((_octant) |= YMAJOR)
+
+#define FIXUP_ERROR(_e, _octant, _bias) \
+    (_e) -= (((_bias) >> (_octant)) & 1)
+
+#define IsXMajorOctant(_octant)		(!((_octant) & YMAJOR))
+#define IsYMajorOctant(_octant)		((_octant) & YMAJOR)
+#define IsXDecreasingOctant(_octant)	((_octant) & XDECREASING)
+#define IsYDecreasingOctant(_octant)	((_octant) & YDECREASING)
+
+extern _X_EXPORT DevPrivateKeyRec miZeroLineScreenKeyRec;
+
+#define miZeroLineScreenKey (&miZeroLineScreenKeyRec)
+
+extern _X_EXPORT int miZeroClipLine(int /*xmin */ ,
+                                    int /*ymin */ ,
+                                    int /*xmax */ ,
+                                    int /*ymax */ ,
+                                    int * /*new_x1 */ ,
+                                    int * /*new_y1 */ ,
+                                    int * /*new_x2 */ ,
+                                    int * /*new_y2 */ ,
+                                    unsigned int /*adx */ ,
+                                    unsigned int /*ady */ ,
+                                    int * /*pt1_clipped */ ,
+                                    int * /*pt2_clipped */ ,
+                                    int /*octant */ ,
+                                    unsigned int /*bias */ ,
+                                    int /*oc1 */ ,
+                                    int /*oc2 */
+    );
+
+#endif                          /* MILINE_H */